We propose a coordinated program of research aimed at elucidating new strategies in the selective control of insect pests and vectors of disease. The investigation will be carried out for the most part on the tobacco hornworm, Manduca sexta -- a large lepidopteron which will be cultured throughout the year on a synthetic diet. The endocrine system will be studied in particular detail with special reference to the actions and interactions of the brain, the prothoracic glands, and the corpora allata in the control of insect growth, metamorphosis, reproduction, and behavior. Our central objective is to discover Insect Growth Regulators which, unlike the presently available juvenile hormone analogs, can derail the growth of immature larval insects. These are cogent reasons for believing that materials with anti-juvenile hormone activity will have this ability. Thus, an anti-juvenile hormone would oppose or prevent the action of endogenous hormone and thereby provoke precocious, lethal metamorphosis of immature larval insects.